In vivo capsular bag size in children with congenital cataract: implications for placement of intraocular lens

To measure the equatorial lens diameter in vivo and correlate it with other biometric variables in children undergoing cataract surgery.

Tertiary care institution.

Prospective case series.

Children younger than 5 years with cataracts were included. Those with corneal opacities, previous ocular surgery, traumatic cataracts, and/or any coexisting corneal or retinal ocular pathology were excluded. In addition to routine investigations, all patients underwent ultrasound biomicroscopy of both eyes. Correlation between the measured value of axial length (AL), corneal diameter, age, and bag diameters and their effect on intraocular lens (IOL) implantation (aphakia/pseudophakia) were observed.

We included 112 eyes of 68 children with a mean age of 11.42 ± 11.34 months (1 month to 4 years). Mean capsular bag diameter (CBD) in the eyes where IOL was placed successfully in the bag was 8.27 ± 0.6 mm (7.1 to 9.39 mm). The eyes in which IOL placement was difficult in the bag and who either were left aphakic or had bicapsular capture IOL placed had a mean diameter of 7.09 ± 0.99 mm (5.23 to 9.09 mm) ( P < .05). A significant and positive correlation was found between CBD and age, AL, and corneal diameter ( P = .00; 0.00; 0.001 and r = 0.4, 0.4, and 0.8, respectively). Bag diameter had the highest association (odds ratio 4) with successful IOL placement.

Bag diameters should be measured preoperatively in children with cataracts along with other biometric variables as it is the most important measurement that helps in making a decision regarding implantation and positioning of IOL.